1. Field
Example embodiments relate to a triple endorectal ballooning (TERB) system in the rectum. More particularly, example embodiments relate to a TERB system in the rectum for prostate cancer radiotherapy.
2. Description of the Related Art
External beam radiotherapy as a typical treatment for prostate cancer has non-invasive characteristics and low side effects. A highly accurate radiotherapy technique such as intensity modulation has amplified this advantage. However, a radiation toxicity to the rectum or anus may be increased according to dose escalation scheme. Recently, rectal ballooning method is preferred in order to decrease the recto-anal radiation toxicity.
Previous ballooning systems being used for prostate cancer treatment may not be applied to patients who have different rectal anatomies and functions. Further, it is difficult to standardize the ballooning system due to different manufacture and authorization system. In many cases, the balloon cannot be accurately located in the rectum due to feces and bowel gas. Further, balloon insertion is dependent upon subjective experiences and feelings of medical operators without standardized protocol. Thus, the balloon cannot be localized at the optimal position reproductively in the rectum. This unstable balloon localization may cause repeated and consumptive results for the patient and medical personnels.
One of the most significant factors of unstable balloon localization is unpredictable bowel gas status.
The entrant single endorectal ballooning system generally have only one central passage way, which makes bowel gas excretion less effective. Because of the cost problem, the balloon may not be used disposably. In this case, the gas excretion can be more difficult due to gas passageway obstruction resulted from hygiene-aimed condom use.
When the endorectal balloon is inflated with air, the actual rectal wall dose may be decreased compared with planned dose due to the specific gravity difference between the air and the rectal wall. This means the possibility of improper prostate cancer treatment despite effective recto-anal wall protection. In contrast, when the injected medium is composed of water, the posterior prostatic dose can be relevant at the expense of rectal wall toxicity increase. This is also the limitation, of the conventional single endorectal ballooning system.